Buildings consume 36% of the total energy consumed in the US and two-thirds of the electricity generated nationally. A building envelope technology that can reduce space conditioning energy consumption significantly will have a significant impact on the energy consumption. Another significant attribute of an improved building construction system is that it should require generally unskilled labor for the envelope construction.
Current structural insulated panels (SIPs) are Oriented Strand Board (OSB) clad, polystyrene foam core, 4×8′ panels. The OSB outer skin is not impervious to termites nor moisture. In order to achieve the desired R-value of at least R-20, the polystyrene core has to be generally 6″ thick. This thickness creates compatibility problems with other structural components such as windows and door frames, and are therefore more expensive and not readily available. The OSB clad SIPS are heavy, sometimes 90-100 lbs, or 2.8 to 3 lbs/sf. In most existing SIP technologies, the interlocking panel-connecting mechanism is not easily assembled and is not airtight. Construction requires uniquely skilled contractors and a crane to install roof panels on even single story buildings. These characteristics add up to higher construction costs, slower production and long term maintenance issues relating to termites, moisture related wood deterioration, and indoor air quality issues from organic resins and mold contamination.